This invention relates to a fiber mulch for application to seed beds.
Various types of mulches are commonly applied over seed beds. The purpose of these mulches is to increase seed germination and decrease soil erosion to allow the seedlings to become firmly established in the seeded area. These mulches typically consist of natural materials such as straw, wood shavings, or paper. The mulches are mixed with water and agitated in a holding tank, and then sprayed onto the seed bed. Some such mulches are woven into blankets that are designed to be laid down over seed beds.
Such mulches are somewhat effective. They do absorb and retain some water, thus keeping the seed bed more hydrated then when mulch is not used. They additionally deflect some of the rain, thereby decreasing to some extent soil erosion. However, most such mulches are loose configurations of unbonded fibers that easily wash away. The paper-based mulches tend to bond into a paper mache-like mat that inhibits oxygen and sunlight transfer, and the ability of seedlings to emerge through the mulch, thus affecting the vegetation establishment.
There have also been introduced into the market chemically bonded natural fiber spray-applied mulches. These mulches use a vegetable gum binder such as guar gum to bind together natural fibers. Although this mulch is extremely well bonded, it has not been successful for a number of reasons. The chemically-bonded mulch forms an almost impenetrable layer over the seed bed that is poor at passing the needed oxygen and water through to the seed bed, and is also very difficult for the germinated seedlings to penetrate. Accordingly, the results for this product have been poor.
It has previously been proposed by the present inventor to provide mulches employing natural fibers derived from straw, wood, etc., along with crimped thermoplastic polyester fibers which, following application, link together to form a coherent matrix which is still open enough to admit light and air. However, the crimped polyester fibers have been shown to decompose but slowly, if at all, in the soil, and thus, even though present in relatively small quantities, are not environmentally optimal. Natural fibers are biodegradable, but have not been used in crimped form. The crimping of natural fibers is ordinarily not permanent, and thus the ability of the fibers to interlock is destroyed as the fibers are exposed to light and moisture, particularly to the water in the mulch tank.